1. Field of the Invention
The invention relates to a series of novel silicone lactylates and their application as emulsifiers for a variety of oil phases. This class of compounds are prepared by the reaction of a carboxy functional silicone and the hydroxyl group of lactic acid. The products provide unique surfactant properties, specifically emulsification properties for many oil phases.
The compounds are useful for preparation of ultra mild products for use personal care applications for skin, hair care and related applications.
2. Arts and Practices
Silicone compounds have been known to be active at the surface of cellulosic and synthetic fibers as well as paper. They are good nondurable lubricants and are very stable to oxidation, however, their high cost and lack of efficiency at low concentrations as well as low durability have made their acceptance in commercial products quite low.
Many oil phases, which are insoluble in water, are emulsified to provide milky white opaque liquids which are easily formulated into a variety of applications. One problem here is that in order to obtain the necessary emulsion stability, relatively high loadings of traditional fatty surfactants are added. This minimizes the amount of oil phase delivered to the hair and skin and affects the feel on the skin and hair.
Carboxy functional silicone compounds useful as raw materials in the practice of the present invention are known to those skilled in the art. U.S. Pat. No. 4,844,888 issued in 1989 to Zawadizki discloses the carboxy functional silicone compounds useful as raw materials in the preparation of the compounds of the present invention.
Fatty lactylates are also known. U.S. Pat. No. 3,883,669 to Tsen et al, teaches the method of making lactylate salts. The methodology includes a reaction of fatty acid with lactic acid. The methodology is directed toward fatty derived materials. The present invention is aimed at making silicone based materials that provide not only the emulsification properties, but also provide conditioning and softening properties to hair. These properties are lacking in traditional lactylates.
U.S. Pat. No. 4,146,548 to Forsythe, incorporated herein by reference, describes an improved method of preparation of lactylates.